The present invention relates generally to the field of endoscopy. More particularly, the present invention relates to improved endoscopic and catheter imaging.
Small imaging devices have become particularly useful in medical diagnostic and treatment applications. Portions of human anatomy previously viewable only by a surgical procedure can be viewed now by a minimally invasive catheterization, provided an imaging device can be made that is small enough to view the target anatomy.
Other uses for very small imaging devices are recognized. For example, such devices can be used and are desirable for surveillance applications, for monitoring of conditions and functions within devices, and for size- and weight-critical imaging needs as are present in aerospace applications, to name a few.
While the present invention has applications in these aforementioned fields and others, the medical imaging application can be used to favorably illustrate unique advantages of the invention. The desirability of providing imaging at sites within the anatomy of living creatures, especially humans, distal of a small orifice or luminal space has long been recognized. A wide variety of types and sub-types of endoscopes have been developed for this purpose.
One advance in imaging technology which has been significant is the increased reduction of individual component sizes. Presently, charged coupled devices (CCD) such as miniature cameras can be manufactured so as to fit on the end of a catheter approximately the size of a couple of strands of wire. Lenses, optical fiber, and miniature surgical equipment can also be produces in miniature dimensions. However, these devices although functional and increasingly effective, can be difficult to position in order to appropriately image small areas of a target tissue.
For example, small cell carcinoma tends to start in the larger breathing tubes of the lungs. In its early stages it may only affect a small number of cells, covering a distance of only 20-40 microns across. Because it could be advantageous to image and diagnose this problem in this early stage before it rapidly grows and becomes quite large it is important to be able to access, locate and image these small areas. High resolution imaging can effectively view these cells if such locations can be found and if the imaging device can be appropriately positioned, focused, and imaged. This process is increasingly complicated in cases, such as small call carcinoma, wherein the cell clusters are located in large passageways. While a larger endoscope could be used for this procedure, a small catheter will substantially minimize patient trauma and duress. Presently, a user will be required to repeatedly move a small catheter or endoscope forward-and-backward, side-to-side in a trial and error fashion in attempts to acquire the target area within focus of the miniature camera. Typically, this process results in images that are not in complete focus and that can be difficult to diagnose.